Plastic molded center tube assembly

ABSTRACT

A filter for a fluid system includes a housing having an interior cavity. A filter media is disposed in the housing and defines a central opening. A center tube assembly is arranged within the central opening and includes discs which are stackable upon one another. Each disc includes a central portion having base received by an inner wall of the central portion of the adjacent disc. An outer portion extends radially outwardly from the central portion and is positioned adjacent to the filter media. The central portion, base, and outer portion may include openings to permit the flow of fluid through the center tube assembly. The center tube assembly provides the desired structural integrity while permitting fluid to flow through the center tube. The present invention center tube assembly may be produced by a plastic molding process.

BACKGROUND OF THE INVENTION

[0001] This invention relates to a filter for use in fluid systems, andmore particularly, the invention relates to a center tube commonly usedin filters.

[0002] Filters are typically constructed from a housing of one or morecomponents secured to one another. A filter media, which is typically apleated type filter media, is disposed within the interior cavity of thehousing. The filter media is typically cylindrical in shape with theexterior of the filter media defining an input side through which dirtyfluid enters. The interior of the filter media defines an outlet sidethat receives the clean fluid.

[0003] A center tube is typically arranged centrally within the filterrelative to the filter media to hold the shape of the filter media andprovide strength to the filter. The center tube is typically constructedfrom metal. Center tubes of different diameters and lengths are producedfor various sized filters. As a result, a high inventory of center tubesis required for the different filters. Furthermore, numerous individualdies, rollers and sealing equipment are required for producing each ofthe center tubes for the various filters.

[0004] Therefore, what is needed is a center tube that permits the flowof fluid therethrough while being able to accommodate differentdiameters and lengths needed for the various filters.

SUMMARY OF THE INVENTION AND ADVANTAGES

[0005] A filter for a fluid system includes a housing having an interiorcavity. A filter media is disposed in the housing and defines a centralopening. A center tube assembly is arranged within the central openingand includes discs which are stackable upon one another. Each discincludes a central portion having base received by an inner wall of thecentral portion of the adjacent disc. An outer portion extends radiallyoutwardly from the central portion and is positioned adjacent to thefilter media. The central portion, base, and outer portion may includeopenings to permit the flow of fluid through the center tube assembly.The center tube assembly provides the desired structural integrity whilepermitting fluid to flow through the center tube. The present inventioncenter tube assembly may be produced by a plastic molding process.

[0006] Accordingly, the above provides a center tube that permits theflow of oil therethrough while being able to accommodate differentdiameters and lengths needed for the various filters

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] Other advantages of the present invention can be understood byreference to the following detailed description when considered inconnection with the accompanying drawings wherein:

[0008]FIG. 1 is a partial cross-sectional perspective view of thepresent invention filter;

[0009]FIG. 2 is a top view of the filter shown in FIG. 1;

[0010]FIG. 3 is a cross-sectional view of the filter shown in FIG. 2taken along lines 3-3;

[0011]FIG. 4 is a side perspective view of one of the discs of thecenter tube assembly shown in FIG. 3; and

[0012]FIG. 5 is a side perspective view of a disc similar to that shownin FIG. 4 with an extended outer portion.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0013] A filter 10, shown in FIG. 1, is typically used for filteringfluid such as in a lubrication system for an engine. The filter 10includes a can or housing 12 that may be constructed from one or morecomponents secured to one another. For example, a nut plate 14 may besecured to an outer cylindrical wall portion with a seam 18. An O-ring16 is placed on the nut plate 14 to seal between the filter 10 and amounting adaptor (not shown).

[0014] The filter 10 includes an interior cavity 20 with a filter media24 disposed within the cavity 20 to filter debris from the fluid so thatclean fluid may be returned to the engine, such as for lubrication ofengine components. The filter media 24 may be of a generally cylindricalshape and is typically pleated to form inner edges 25 that define acentral opening 27. The filter media 24 is typically retained betweenend caps, which are not shown for clarity. The filter media 24 has aninlet side 26 that receives dirty fluid and an outlet side 28 whereclean fluid exits the filter media 24. The nut plate 14 may includeperforations 22 to permit dirty fluid to enter the filter 10. Nut plate14 may also include a threaded aperture 34 that is used to secure thefilter 10 to the mounting adaptor. The clean fluid exits the centralopening 27 through the threaded aperture 34 and into the mountingadaptor.

[0015] It should be understood that the fluid flow may be reversed fromthat described above. Furthermore, the present invention center tubeassembly may also be used with a cartridge type filter typically locatedwithin a suitable fixed housing. The filter media is retained betweenspaced apart end discs, such that the outer perimeter of the filtermedia is left exposed. Such a filter arrangement is well known in theart. Moreover, it is to be understood that the present invention centertube assembly, discussed below, may be used in any suitable filterconfiguration.

[0016] A center tube assembly 35 is disposed within the central opening27 to provide structural integrity to the filter 10 and permit fluid topass through the center tube assembly 35 to the mounting adaptor. Thecenter tube assembly 35 is arranged proximate to the filter media 24 toprovide support to its inner edges 25 to maintain the shape of thefilter media 24. The center tube assembly 35 includes discs 36 that arestacked to a desired height. Referring to FIGS. 2-4, the center tubeassembly 35 includes a central portion 37 that may be any desirableshape. The central portion 37 may include spaced apart vertical walls 38defining openings 39. The central portion 37 further includes a base 40that is indented or recessed radially from the vertical walls 38 and isreceived by an inner wall 41 of the adjacent disc 36. The base 40includes arms 42 extending between the vertical walls 38 to providestructural rigidity. The arms 42 define openings 43 to permit the flowof fluid therethrough. An outer portion 46 may extend radially outwardlyfrom the central portion 37. The outer portion 46 includes an annularwall 52 connected to the central portion 37 by legs 50. The legs 50,annular wall 52, and central portion 37 define openings 53 that permitthe flow of fluid therethrough. Fins 44 may be interconnected betweenthe central portion 37 and the outer portion 46 to provide additionalstructural rigidity to the discs 36.

[0017] The length of the central portion 37 may be varied to providedifferent length discs 36 suitable for multiple filters. Moreover, acombination of discs 36 having different length central portions 37 maybe used to achieve a desired length of the center tube assembly 35.Similarly, different size outer portions 46 may also be used to providevarious diameters of the center tube assembly 35, as best shown in FIG.5.

[0018] Preferably, the center tube assembly 35 of the present inventionis constructed from a plastic. The center tube 35 may be produced by amolding process. A dedicated mold may be used to produce a disc having adefined central portion length and outer portion diameter. Various moldsmay be used to provide sets of various sized discs that may be mixed ormatched to provide a center tube assembly of a desired length anddiameter. A mold may contain various inserts to provide different lengthcentral portions 37 and different diameters of the outer portion 46 sothat only one mold may be needed, as will be appreciated of one ofordinary skilled in the art. Furthermore, the disc 36 shown in FIG. 5may be trimmed to provide a disc of the diameter shown in FIG. 4 so thatone mold may provide discs of different diameters. Alternatively, a moreversatile mold may be used having inserts to vary the central portionlength and outer portion diameter, as would be appreciated by one ofordinary skilled in the art.

[0019] The invention has been described in an illustrative manner, andit is to be understood that the terminology that has been used isintended to be in the nature of words of description rather than oflimitation. Obviously, many modifications and variations of the presentinvention are possible in light of the above teachings. It is,therefore, to be understood that within the scope of the appended claimsthe invention may be practiced otherwise than as specifically described.

What is claimed is:
 1. A filter for a fluid system comprising: a housinghaving an interior cavity; a filter media disposed in said cavitydefining a central opening; and a center tube assembly disposed in saidcentral opening and including first and second discs stacked togetherwith said discs terminating in an outer portion adjacent to said filtermedia.
 2. The filter according to claim 1, wherein said filter media ispleated forming inner edges proximate to said outer portion.
 3. Thefilter according to claim 1, wherein said filter media includes inletand outlet sides with said center tube assembly disposed on said outletside.
 4. The filter according to claim 1, wherein each of said discsincludes a central portion defining a length and an outer portionextending radially outwardly from said central portion defining adiameter.
 5. The filter according to claim 4, wherein said outer portionincludes an annular wall connected to said central portion by legs withsaid legs, said annular wall, and said central portion definingopenings.
 6. The filter according to claim 4, wherein said centralportion of one said discs includes a vertical wall with a base indentedfrom said vertical wall and received by an inner wall of said centralportion of another of said discs.
 7. The filter according to claim 6,wherein said vertical wall includes a plurality of openings, and saidbase includes a second opening.
 8. A center tube assembly for an oilfilter comprising: a first disc and a second disc removably engaged withsaid first disc with each of said discs including a central portiondefining a length and an outer portion extending radially outwardly fromsaid central portion defining a diameter.
 9. The center tube accordingto claim 8, wherein said outer portion includes an annular wallconnected to said central portion by legs with said legs, said annularwall, and said central portion defining openings.
 10. The center tubeaccording to claim 8, wherein said central portion of one of said discsincludes a vertical wall with a base indented from said vertical walland received by an inner wall of said central portion of another of saiddiscs.
 11. The center tube according to claim 10, wherein said verticalwall includes a plurality of openings, and said base includes a secondopening.
 12. The center tube according to claim 8, wherein said discsare plastic.
 13. A method of assembling a filter comprising the stepsof: a) providing a filter media having a central opening; b) stacking afirst disc onto a second disc forming a center tube assembly; and c)inserting the center tube assembly into the central opening.
 14. Themethod according to claim 13, wherein discs include a central portiondefining a length and an outer portion extending radially outwardly fromthe central portion defining a diameter.
 15. The method according toclaim 14, wherein the discs define a desired center tube assembly lengthand a desired center tube assembly diameter.